in der Spongiologie während der Jahre 1888 — 1891. 221 



Subfam. Sanidasterina. 



Heterastrose Stellettidae in which the additional micro- 

 sclere is a sanidaster or amphiaster. 

 Gen. Ancorina (0. Schm), Tribracbium Weltn. emend. Sollas, 

 Disyringa Soll., Tetbyopsis Stewart, Strypbnus Sollas. 

 Appendix to the Euastrosa: Fam. Epipolasidae Sollas. 



Gen. Amphius Sollas, Asteropus Sollas, Coppatias Sollas. 

 DemusIII: Sterrastrosa Sollas. 



Astrophora in whicb the characteristic microsclere is a 

 sterraster. 

 Fam. Geodiidae Gray. 



Sterrastrosa possessing triaene megascieres. 

 Subfam. Erylina. 



Tbe megascieres are orthotriaenes and rbabdi; ana- 

 triaenes and protriaenes are absent. The soma mi- 

 crosclere is a diactinate aster or spberule. 

 Gen. Erylus Gray, Caminus 0. Schm., Pachymatisma Bwk. 

 Subfam. Geodina. 



The megascieres are rhabdi, ortho, or dicbotriaenes, 



and frequently in addition pro and anatriaenes. The 



sterraster is sphaerical or ellipsoidal ; the somal 



microsclere is a polyactinose aster. 



Gen. Cydonium Flem., Geodia (Lm.j, Syuops Vosm., Isops Soll. 



Fam. Placospongidae Gray. 



Sterrastrosa not possessing triaene spicules; the onlymegasteres 

 are tylostyles. The sterrastral layer of the cortex is sub- 

 divided into regulär or polygonal plates, which are united 

 together by fibrous tissue. 

 Gen. Placospongia Gray. 

 Suborder III : Microsclerophora. 



Choristida in which megascieres are absent; the charac- 

 teristic microscleres are either tetractinose asters, cande- 

 labra, or minute triaenes. 

 Fam. Placinidae F. E. Schulze. Microsclerophora with tetractinose, 

 triactinose, and diactinose asters, and sometimes mono, di, or 

 trilophous candelabra. The chamber-system is either eurypylous 

 or aphodal; the mesoderm chiefly collenchymatous. The Sponge 

 is divided into a hypophare and spongophare. 

 Gen. Placina F. E. Schulze. Placortis F. E. Schulze. 

 Fam. Corticidae Vosm. 



Microsclerophora whith tetractinose asters and candelabra. The 

 chamber-system is aphodal or diplodal. The mesoderm is in 

 part sarcenchymatous, in part chondrenchymatous. 

 Gen. Corticium O. Schm., Calcabrina Sollas, Corticella Sollas, 

 Rachella Sollas. 

 Fam. Thrombidae Sollas. 



Microsclerophora with trichotriaenes , and sometimes a peculiar 

 form of amphiaster. The ectosome is thin and not sharply 



